Electromagnetically operated device



Jan. 23, 1951 G. H. LELAND ELECTROMAGNETICALLY OPERATED DEVICE Filed May18, 1948 INVENTOR. 62. 0565 1 f2 fl/VP Patented Jan. 23, 1951ELECTROMAGNETICALLY OPERATED DEVICE George H. Leland, Dayton, Ohio-Application May 18, 1948, Serial No. 27,794

3 Claims.

This invention relates to an electromagnetically operated device andmore particularly to a rotary solenoid of the type shown and describedin my pending application Serial Number 542,188 filed June 26, 1944, nowPatent No. 2,496,880.

A rotary solenoid of this type comprises a magnet and an armature whichis moved axially by the magnet, and is provided with means whereby theaxial movement of the armature serves to impart rotary movement thereto.This means usually comprises a wall or plate fixed with relation to themagnet and a rotatable plate rigidly connected with the armature formovement therewith. The two plates are arranged in substantiallyparallel spaced relation and are provided with a plurality of pairs ofarcuate inclined surfaces, the inclined surfaces of each *pair beingincl ned in opposite directions and preferably constituting the base orbottom surfaces of arcuate grooves. Mounted in each pair of grOOVGS isan anti-friction device, preferably a ball, and the arrange ment of theinclined surfaces is such that the pressure of the rotatable plateexerted on the balls by the axial movement of the armature will causethe plate and, therefore, the armature to rotate and to impart movementto a shaft or other device connected with the armature for operationthereby. The magnet is deenergized at the end of each power transmittingmovement of the armature. The armature is returned to its initialposition by a spring and the magnet is again energized to impart asecond power movement to the armature. When the deenergization and thereenergization of the magnet are automatically conrolled the armature iscaused to oscillate continuously, as shown in my application SerialNumber 760,029, filed July 1'0, 1947, now Patent No. 2,501,950. Inmagnetically operated devices of this kind as heretofore constructed ithas been customary to use a long coil spring for returning the armatureto its initial position, that spring being connected at one end eitherdirectly or indirectly with the arrnature, off center, and. beingconnected at its other end with a fixed part more or less remote fromthe armature, such as a part of the structure on which the device ismounted. Such a return s ring, while satisfactory for many purposes, islimited in its operation and has certain undesirable features.

The main object of the invention is to provide a return spring of arelatively small, compact character which can be built into theelectromagnetic device.

A further object of the invention is to provide such a spring which willhave a range of operas.

2 tion much greater than the range of operation of springs'heretoforeemployed for this purpose, thus permitting a longer rotary movement ofthe armature, upon each operation thereof, than has been heretoforepossible.

A further object of the invention is to provide such a spring which willhave substantially constant tension throughout its operation.

A further object of the invention is to provide such a spring which willbe substantially frictionless.

A further object of the invention is to provide such a spring which canbe adjusted to vary the tension thereof without removing it from thedevice on which it is mounted.

A further object of the invention is to provide such a return springwhich will also function as a preloading spring to maintain therotatable plate in firm engagement with the anti-friction elements whenthe magnet is deenergized.

A further object of the invention is to provide such a return springwhich will positively l mit the axial movement of the rotatable platefrom the fixed plate when the magnet is deenergized.

Other objects of the invention may appear as the device is described indetail.

In the accompanying drawings Fig. 1 is a front elevation of a rotarysolenoid embodying my invention, with the cover partly broken away: Fig.2 is a section taken on the line Z--2 of Fig. 1; Fig. 3 is a detailsection showing one pair of inclined surfaces; Fig. 4 is an elevation ofthe return spring; Fig. 5 is an edge view of the spring; Fig. 6 is anelevation of the plate with which the spring is connected; Fig. 7 is'anedge view of the plate; Fig. 8 is a detail view showing the connectionbetween one end of the spring and the plate; and Fig. 9 is a detail viewof a portion of a modified form of shaft to which the spring isconnected.

In these drawings I have illustrated one em-.

bodiment of my invention and have shown the same as embodied in a rotarysolenoid of a construction similar to the rotary solenoid shown anddescribed in my application filed of even date herewith, Serial Number27,795. It is to be understood however that the spring may take variousforms and may be applied to electromagnetic devices of various kinds,without departing from the spirit of the invention.

In the particular embodiment here'illustrated the electromagnetic deviceis shown as a rotary solenoid comprising a supporting structure orcasing consisting of an outer cylindrical mem- .bcr It, a rear end wallH rigidly connectedwith M and in the present instance mounted in therear end of the cylindrical member with a pressed fit. Mounted in theforward portion of the cylindrical member H) is a front wall or annularplate 12 which is rigid with the member H2. The rear end member II isprovided with a bearing [3 in which a shaft [4 is mounted, the shaft inthe present instance being capable of both 1'0- tary movement and axialmovement. The back wall is provided with an inwardly extending partconstituting the core and the bearing extends through this core. Theshaft extends forwardly beyond the core and an armature I6 is connectedwith the shaft for rotary and axial movement therewith, preferably byrigidly mounting it on the shaft. The armature is here shown asextending through the annular plate I2 and a short distance beyond thesame. Rig-idly secured to the armature, for both rotary and axialmovements therewith is a second plate i! which projects radially beyondthe armature and is arranged in parallel spaced relation to the fixedplate 12; The rotatable plates and the fixed plate are provided with aplurality ofpairs of inclined surfaces, these surfaces in the presentinstance constituting the bottom walls of grooves l8 and i9. formed,respectively, in the rotatable plate I! and the'fixed plate [2. Thesurfaces of each pair of inclined surfaces are inclined in oppositedirections and an anti-friction device, such as a ball 20, is arrangedbetween the inclined surfaces of each pair. Arranged between the fixedplate l2 and the marginal portion of the back plate H, and extendingabout the core and a portion of thearmature, is a magnetizing element orcoil 21 which energizes the magnet and imparts axial movement to thearmature. When the magnet is deenergized the shallow ends of the twooppositely inclined surfaces of each pair" are adjacent one to the otherand the anti-friction element is between-the shallow ends of' thesurfaces; When the magnet is energized the axial movement of the.armature causes the rotatable plate I? to press on the severalanti-friction elements in such a manner a that the rotatable plate iscaused to rotate simultaneously with its axial movement, therebyimparting both rotary movement and axial movement to the armature andthe shaft. In the present instance the back plate I l is provided withsockets to receive screws 22 by which the device may be connected with asupporting structure. If desired a dust cover 23 may be removablymounted on the forward end of the cylindrical member Hi to enclose thearmature and its associated parts.

The means for controlling the magnet circuit are not here shown but theymay be of any suitabie character which will open the circuit at the endof the rotation of the armature by the magnet and again close the crcuit when the armature is returned to its initial position, such as.the circuit breakers and closers shown in either of the above mentionedapplications. It will be understood, of course, that a master switch isconnected in the circuit tov start and stop the operation of thesolenoid and" when the master switch is closed the armature willoscillate continuously and at high speed.

The return spring is shown at 24 as a spiral spring which is connectedat its inner end with the shaft !4 and is connected at its outer endwith an anchoring device which is fixed with relation to the magnet. Inthe present instance the spiral spring is conical in form, for a purposewhich will hereinafter appear. The inner end of the spring may beconnected with the shaft [4 in any suitable manner. In the arrangementhere shown the shaft is provided with a transverse notch 25 and theinner convolution26of the spring fits snugly about the shaft and has itsinner end turned inwardly, as shown at 21, to extend into the notch 25and thus firmly secure the end of the spring to the shaft for rotationtherewith. The end walls of the notch 25 are preferably parallel and ofa width approximating the width of the inner convolution of the springso that the spring rotates with the shaft and the inner ccnvolutionsmove axially with the shaft.

The outer end of the spring may be anchored in anysuitable manner, as bya lug or projection connected with and extending from the magnet, withwhich the end of the outer convolution 3| is connected. In theparticular construction here illustrated a plate 28, preferably of thinmetal, is supported on or adjacent to the rear wall of the magnet, as bymounting it on't'ne attaching screws 22. This plate is provided with anaxial opening 29 through which the shaft extends and which is of adiameter substantially greater than the diameter of the shaft. Theanchoring plate 28 is provided at the edge of the opening 29 with aseries of lugs 39. In the present instance these lugs are integral withthe plate and are arranged in'an annular series about the opening 29.They may be formed in any suitable manner, as b a stamping operation ona flat plate to form thereon inwardly extending radial lugs which arethen bent outwardly to the positions shown in Fig. 7. The diameter ofthe opening approximates the over all diameter of the spiral spring sothat when the spring is mounted on the shaft the outer convolution 3|thereof lies within the series of lugs and will have contact with atleast apart of thoselugs. As best shown in Fig. 4 the end of the outerconvolution extends beneath and beyond one of the lugs and in contactwith the inner surface of that lug and is provided on that part thereofwhich extends beyond the lug with a part 32 adapted to engage theadjacent edge of the lug and thus hold the end of the spring againstrearward movement, that is prevent it frommoving when the innerconvolutions are rotated to place'the spring under tension. The part 32may be of any suitable character but it is here shown as a rearwardlyextending finger struck from the end portion of the outer convolutionand arranged with its rear end in engagement with the adjacent edge ofthe lug. Preferabl the forward edge of the lug 3% is recessed to receivethe rear end of the finger 32 and thus prevent the relative lateraldisplacement of the finger and of the end portion of the outerconvolution. As will be noted particularly in Figs. 7 and 8 both sidesof each lug are provided with curved recesses 33. and the end of thefinger 32 is curved to fit in the recess of any lug.

While I have shown an annular series of lugs this is not essential and ashorter series of lugs or a single lug may be employed for anchoring theouter end of the spring. By the use of a series-of lugs-theouterconvolutions of the spring may be adjustedto vary the tension of thespring. The finger 32 being resilient may be depressed andrnoved eitherforwardly or rearwardly beneath an adjacent lug and brought intooperative engagement with another lug, thus tightening or loosening theouter convolution. The annular series of lugs on the anchor plate beingin contact 7 with or close to the outer convolution of the spring retainthat convolution and the adjacent convolutions substantially concentricwith the axis of rotation of the shaft, t ereby eliminating frictionbetween those convolutions. Due to the connection of the end of theouter convolution with the fixed support on the outer side of and closeto the outer convolution the winding of the spring by the shaft to placethe spring under tension does not tend to laterally displace the springor to press the convolutions on one side of the shaft into cngagel entone with the other, as usually results when the end of the outerconvolution is anchored at a point spaced 2. substantial distance fromthe spring. As a result there is very little frictional contact betweenthe convolutions of this spring. The outer convolution has contact withthe adjacent convolution but in the operation of the device these twoconvolutions have very little relative movement. The inner-mostconvolution also has some contact with the adjacent convolution but therotation of the shaft to place the spring under tension does not drawthe other convolutions into ongagement one with the other sufficientlyto offer any material resistance to the contraction or expansion of thespring. It will be obvious, of course, that the connection between thespring and the shaft is such that the rotation of the shaft by thearmature will wind the spring and place the same under tension and uponthe deenergization of the magnet the spring will rotate the shaft andthus return the armature and the anti-friction elements to their initialpositions. Therefore, it will be apparent from the character of thespring that the armature can have a very long range of rotarymovement,as the onlylimitaticn of that movement would be the complete winding ofthe spring, and the spring is of such a size as to permit of relativelylong movement. One of the objectionable features to the old type ofreturn spring was that it definitely limited the distance to which thearmature could be rotated. without moving the point at which the springis connected with the armature across center. The present spring is freefrom any such limitation. Not only is the spring substantiallyfrictionless but it also has substantially constant tension. Due to thespiral winding and arrangement of this spring the resistance to theoperative movement of the shaft increases very slightly as the shaftapproaches the end of its movement. In the old type of return springthere a very substantial increase in tension before the armature hascompleted its movement. The spring can be adiusted to increase ordecrease the tension thereof very easily without removing the springfrom the device, it being only necessary to detach the device fro-rn itssupporting structure so as to gain access to the rear side thereof. Theinner convolutions of the spring being connected with the shaft foraxial movement therewith while the outer convolution is held againstaxial movement, it will be apparent that the axial movement of the shaftdisplaces the inner convoluticns axially with relation to the outerconvolutions and the spring thus yieldably resists the axial movement ofthe shaft. As a result the rotatable plate I? is at all times held infirm engagement with the anti-friction device and there is noopportunity for these anti-friction devices to become displaced duringthe return movement of the armature after deenergization. Such dsplacement of the anti-friction elements would leave them in improperpositions for operation upon the next energization of the magnet, Whenthe anti-friction devices are preloaded in the manner described they arenot subject to displacement. Further the inner convolutions of thespring are so arranged with relation to the shaft that when the shaft isin its foremost position, that is the position to which it moves whenthe magnet is deenergized, these inner convolutions will engage a partfixed with relation to the magnet, in the present instance the end ofthe bearing 13, thereby limiting the forward axial movement of theshaft, and avoiding any possibility of the rotary plate ll being at anytime moved to a position with relation to the fixed 52 which wouldpermit the escape of the anti-friction elements.

In Fig. 9 I have shown a slightly different arrangement of the notch inthe shaft which is desirable when a ratchet Wheel or the like is to besecured to the shaft. As there shown the shaft it" is provided at itsforward end with a reduced portion or axial stud 34% on which theratchet wheel or other device may be mounted and the notch 25" is formedat the forward end of the body of the shaft and the ratchet Wheel orother device mounted on the stud lid serves to close the outer end ofthe recess.

While I have shown and described one embodiment of my invention. I wishit to be understood that I do not desire to be limited to the detailsthereof as various modifications may occur to a person skilled in theart.

Having now fully described my invention what I claim as new and desireto secure by Letters Patent is:

l. A magnetically operated device comprising an electromagnet, anarmature movable axially by said magnet, a plate fired with relation tosaid magnet, a rotatable plate rigid with said armature and supported inparallel spaced relation to the first mentioned plate, said plateshaving a plurality of pairs of opposed inclined surfaces anti-frictionelements between the surfaces of the respective pairs of inclinedsurfaces, said surfaces being so arranged that the axial movement ofsaid armature by said In agnet will impart rotary movement to saidarmature. a shaft connected with said armature for rotary movement andaxial movement thereby, and a single spring conn cted at one end with afixed part of said device and connected at its other end with said shaftto return said armature to its initial position when said magnet isdeenergized and to urge said shaft in a direction to retain saidrotatable plate in firm contact with said anti-friction elements whensaid magnet is deenergized.

2. A magnetically operated device comprising an electromagnet, anarmature movableaxially by said magnet, a plate fixed with relation tosaid magnet, a rotatable plate rigid with said armature and supported inparallel Spaced. relation to the first mentioned plate, said having aplura ity of pairs of oppose sl'ned surfaces, anti-friction elementsbetween the surfaces of the respective pairs of inclined surfaces, saidsurfaces bein so arranged that the axial movement of said armature bysaid will impart rotary movement to said armature, a shaft connectedwith said armature for rotary movement and ax al movement thereby, aspiral spring wound about said shaft in superposed convolutions, havingits inner end connected with the shaft for rotary movement and for axialmovement therewith, means for anchoring the outer end of said spring ata point fixed with relation to said magnot, the arrangement being suchthat the rota- 75 tion of said shaft by said armature will place said 7-spring under tension and upon the deenergizing of said magnet-saidspring will return said armature to its initial position and-will exertaxial pressure on said shaft to retain said rotatable plate in firmcontact with said anti-friction elements.

3. A magnetically operated device comprising an electromagnet, anarmature movable axially by said magnet, a plate fixed with relation tosaid magnet, a rotatable plate rigid with said armature and supported inparallel spaced relation to the first mentioned plate, said plateshaving a plurality of pairs of opposed inclined surfaces, anti-frictionelements between the surfaces of the respective pairs of inclinedsurfaces, said surfaces being so arranged that the axial movement ofsaid armature by said magnet will impart rotary movement to saidarmature, a shaft connected with said armature for rotary movement andaxial movement thereby, a plate fixed with relation to said magnet atthat end thereof opposite said armature and having an annular series oflugs extending lengthwise of said shaft, a conical spiral spring mountedabout said shaft with the outer convolution thereof within said seriesof lugs, means for connecting said outer convolution with one of saidlugs, means for connecting the inner convolution of said spring withsaid shaft for both axial and. rotary movements. therewith, a part ofthe convolutions of said springbeing arranged to engage a part fixedwith relation to said magnet and limit the axial movement of said shaftwhen said magnet is deenergized, whereby said spring serves to returnsaid armature to its initial position, to yieldaloly urge said shaft inone axial direction and to limit the axial movement of said shaft in theopposite direction.

GEORGE H. LELAND.

REFERENCES CITED The following references are of record in the file ofthis patent:

